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Why is my JSlider not changing the value?

I am trying to make my program so that an integer value entered in a JTextfield can be stored into a variable. Then, when a JButton is clicked, this variable can tell a JSlider to move it's head to that of the integer value stored in the variable. My class name is Camera.Java
Code is showing no errors, however if I click my JButton, nothing happens, instead I see this error in the console:
Exception in thread "main" java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:504)
at java.lang.Integer.parseInt(Integer.java:527)
at Camera.main(Camera.java:67)
My code:
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Hashtable;
import java.util.Scanner;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JPanel;
import javax.swing.*;
public class Camera {
static JButton addtolist;
static Scanner input = new Scanner(System.in);
static JSlider cam = new JSlider();
static JTextField enterval = new JTextField();
static int x ;
public static void main (String args[]){
JFrame myFrame = new JFrame ("Matthew Damon on Mars");
myFrame.setSize(300, 600);
JPanel panel = new JPanel(new FlowLayout(FlowLayout.CENTER));
JLabel userinp = new JLabel("Enter input: ");
cam = new JSlider(0, 15, 0);
cam.setPaintLabels(true);
enterval.setPreferredSize(new Dimension(100,80));
addtolist = new JButton("Enter");
addtolist.setPreferredSize(new Dimension(50,20));
JTextField enterval1 = new JTextField();
panel.add(addtolist);
Hashtable<Integer, JLabel> table = new Hashtable<Integer, JLabel>();
table.put(0, new JLabel("0"));
table.put(1, new JLabel("1"));
table.put(2, new JLabel("2"));
table.put(3, new JLabel("3"));
table.put(4, new JLabel("4"));
table.put(5, new JLabel("5"));
table.put(6, new JLabel("6"));
table.put(7, new JLabel("7"));
table.put(8, new JLabel("8"));
table.put(9, new JLabel("9"));
table.put(10, new JLabel("A"));
table.put(11, new JLabel("B"));
table.put(12, new JLabel("C"));
table.put(13, new JLabel("D"));
table.put(14, new JLabel("E"));
table.put(15, new JLabel("F"));
cam.setLabelTable(table);
myFrame.add(cam, BorderLayout.SOUTH);
myFrame.add(userinp, BorderLayout.NORTH);
myFrame.add(enterval1, BorderLayout.NORTH);
myFrame.add(panel, BorderLayout.CENTER);
myFrame.setVisible(true);
buttonAction();
}
public static void buttonAction() {
addtolist.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
int x = Integer.parseInt(enterval.getText());
cam.setValue(x);
} catch (NumberFormatException npe) {
// show a warning message
}
}
});
}
}

Your setting x on program creation before the user has had any chance to change its value. Get the text value from within the actionPerformed method which should be after the user has already selected a value, parse it into a number and set the slider with that value.
public void actionPerformed(ActionEvent e) {
try {
int x = Integer.parseInt(enterval.getText());
cam.setValue(x);
} catch (NumberFormatException npe) {
// show a warning message
}
}
Then get rid of all that static nonsense. The only method that should be static here is main, and it should do nothing but create an instance and set it visible.
Note that better than using a JTextField, use a JSpinner or a JFormattedTextField or if you're really stuck, a DocumentFilter to limit what the user can enter

Again, you should put most everything into the instance realm and out of the static realm. This means getting most of that code outside of the main method and into other methods and constructors, that means not trying to access fields or methods from the class, but rather from the instance. For instance, your main method should only create the main instances, hook them up and set them running and that's it. It should not be used to build the specific GUI components. For example:
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;
import javax.swing.*;
#SuppressWarnings("serial")
public class CameraFoo extends JPanel {
// only static field here is a constant.
private static String TEXTS = "0123456789ABCDEF";
private JSpinner spinner = new JSpinner();
private JSlider slider = new JSlider(0, 15, 0);
public CameraFoo() {
List<Character> charList = new ArrayList<>();
Hashtable<Integer, JLabel> table = new Hashtable<>();
for (int i = 0; i < TEXTS.toCharArray().length; i++) {
char c = TEXTS.charAt(i);
String myText = String.valueOf(c);
JLabel label = new JLabel(myText);
table.put(i, label);
charList.add(c);
}
SpinnerListModel spinnerModel = new SpinnerListModel(charList);
spinner.setModel(spinnerModel);
slider.setLabelTable(table);
slider.setPaintLabels(true);
JPanel topPanel = new JPanel();
topPanel.add(spinner);
topPanel.add(new JButton(new ButtonAction("Press Me")));
setLayout(new BorderLayout());
add(topPanel, BorderLayout.PAGE_START);
add(slider);
}
private class ButtonAction extends AbstractAction {
public ButtonAction(String name) {
super(name);
}
#Override
public void actionPerformed(ActionEvent e) {
char ch = (char) spinner.getValue();
int value = TEXTS.indexOf(ch);
slider.setValue(value);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
createAndShowGui();
});
}
private static void createAndShowGui() {
CameraFoo mainPanel = new CameraFoo();
JFrame frame = new JFrame("CameraFoo");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
}

Why are JButtons not displaying in a JFrame?

I am trying to develop a voting GUI and I have a main class and a ballot class. The Ballot class extends JPanel and creates buttons inside the class. I am trying to add Ballot objects to the main JFrame but when I run the program, the buttons do not display. Any help would be appreciated. Here is the code.
Assig5.java:
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.WindowConstants;
import javax.swing.BoxLayout;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.Scanner;
import java.util.ArrayList;
public class Assig5 extends JFrame
{
public Assig5()
{
super("E-Vote Version 1.0");
JPanel castVotePanel = new JPanel();
BoxLayout layout = new BoxLayout(castVotePanel, BoxLayout.Y_AXIS);
castVotePanel.setLayout(layout);
ArrayList<String> ballots = new ArrayList<String>();
try{
ballots = readBallotFile("ballots.txt");
}
catch(FileNotFoundException e){
System.exit(0);
}
ArrayList<Ballot> ballotList = addBallots(ballots);
for(Ballot b : ballotList)
{
add(b);
}
castVotePanel.add(createLoginButton());
castVotePanel.add(createCastButton());
add(castVotePanel);
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
pack();
setVisible(true);
}
public static void main(String args[])
{
Assig5 assig5 = new Assig5();
}
public JButton createLoginButton()
{
JButton loginButton = new JButton("Login to Vote");
loginButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
// display/center the jdialog when the button is pressed
String input = JOptionPane.showInputDialog("Please enter your voter ID: ");
}
});
return loginButton;
}
public JButton createCastButton()
{
JButton castButton = new JButton("Cast Vote");
castButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
}
});
return castButton;
}
public ArrayList<Ballot> addBallots(ArrayList<String> ballotContents)
{
ArrayList<Ballot> ballotList = new ArrayList<Ballot>();
for(int i = 0; i < ballotContents.size(); i++)
{
String[] splitBallotContent = ballotContents.get(i).split("[:,]");
String[] options = new String[splitBallotContent.length - 2];
for(int j = 2; j < splitBallotContent.length; j++)
{
options[j - 2] = splitBallotContent[j];
}
Ballot ballot = new Ballot(splitBallotContent[0], splitBallotContent[1], options);
ballotList.add(ballot);
}
return ballotList;
}
public static ArrayList<String> readBallotFile(String filename) throws FileNotFoundException
{
ArrayList<String> list = new ArrayList<String>();
Scanner s = new Scanner(new File(filename));
int numBallots = Integer.parseInt(s.nextLine()); //we need to get to next line
for(int i = 0; i < numBallots; i++)
{
if(s.hasNextLine())
{
list.add(s.nextLine());
}
}
s.close();
return list;
}
Ballot.java:
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.WindowConstants;
import javax.swing.BoxLayout;
import java.awt.*;
import java.awt.event.*;
public class Ballot extends JPanel
{
public Ballot(String ballotID, String title, String[] options)
{
super();
BoxLayout layout = new BoxLayout(this, BoxLayout.Y_AXIS);
setLayout(layout);
add(new JLabel(title, JLabel.CENTER));
for(String s : options)
{
add(new JButton(s));
//add actionlistener here
}
}
}

JFrame uses a BorderLayout, you are adding both the castVotePanel and all the Ballot panels to the same position on the frame (CENTER). You might want to consider using a different layout manager
See How to Use BorderLayout and Laying Out Components Within a Container for more details.
For example...
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
public class Assig5 extends JFrame {
public Assig5() {
super("E-Vote Version 1.0");
JPanel castVotePanel = new JPanel();
BoxLayout layout = new BoxLayout(castVotePanel, BoxLayout.Y_AXIS);
castVotePanel.setLayout(layout);
ArrayList<String> ballots = new ArrayList<String>();
try {
ballots = readBallotFile("ballots.txt");
} catch (FileNotFoundException e) {
System.exit(0);
}
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.weightx = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
ArrayList<Ballot> ballotList = addBallots(ballots);
for (Ballot b : ballotList) {
add(b, gbc);
}
castVotePanel.add(createLoginButton());
castVotePanel.add(createCastButton());
add(castVotePanel, gbc);
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
pack();
setVisible(true);
}
public static void main(String args[]) {
Assig5 assig5 = new Assig5();
}
public JButton createLoginButton() {
JButton loginButton = new JButton("Login to Vote");
loginButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// display/center the jdialog when the button is pressed
String input = JOptionPane.showInputDialog("Please enter your voter ID: ");
}
});
return loginButton;
}
public JButton createCastButton() {
JButton castButton = new JButton("Cast Vote");
castButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
}
});
return castButton;
}
public ArrayList<Ballot> addBallots(ArrayList<String> ballotContents) {
ArrayList<Ballot> ballotList = new ArrayList<Ballot>();
int id = 0;
for (int i = 0; i < 10; i++) {
String[] options = new String[]{"A", "B", "C", "D"};
Ballot ballot = new Ballot(Integer.toString(++id), "Help " + id, options);
ballotList.add(ballot);
}
return ballotList;
}
public static ArrayList<String> readBallotFile(String filename) throws FileNotFoundException {
ArrayList<String> list = new ArrayList<String>();
// Scanner s = new Scanner(new File(filename));
// int numBallots = Integer.parseInt(s.nextLine()); //we need to get to next line
// for (int i = 0; i < numBallots; i++) {
// if (s.hasNextLine()) {
// list.add(s.nextLine());
// }
//
// }
// s.close();
return list;
}
public class Ballot extends JPanel {
public Ballot(String ballotID, String title, String[] options) {
super();
BoxLayout layout = new BoxLayout(this, BoxLayout.Y_AXIS);
setLayout(layout);
add(new JLabel(title, JLabel.CENTER));
for (String s : options) {
add(new JButton(s));
//add actionlistener here
}
}
}
}

JFrame uses BorderLayout by default and your all panels are on center of border that is why its not showing up
Use different positions or different layouts
for more on layouts : https://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html
https://docs.oracle.com/javase/tutorial/uiswing/layout/using.html

How to change image without double instantiating the JFrame?

So I want to change the image showing every time i press the Roll button but whenever I try to do it I double instantiate the JFrame. I would like to use the ActionListener this way if it is posible.
Here is my code:
import javax.swing.JFrame;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JButton;
import javax.swing.JTextArea;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class DiceFrame extends JFrame{
ImageIcon[] dice_images = new ImageIcon[7];
String score = "This is a test";
JPanel mainPanel;
JPanel scorePanel;
JPanel buttonPanel;
JLabel picLabel;
JTextArea scoreField;
JButton roll;
JButton save;
ActionListener action;
ActionListener output;
public DiceFrame(){
super();
mainPanel = new JPanel();
scorePanel = new JPanel();
buttonPanel = new JPanel();
roll = new JButton("Roll");
save = new JButton("Save");
picLabel = new JLabel();
scoreField = new JTextArea();
setSize(400,300);
setTitle("Dice Program");
loadImage();
getContentPane().add(mainPanel, BorderLayout.CENTER);
getContentPane().add(scorePanel, BorderLayout.EAST);
getContentPane().add(buttonPanel, BorderLayout.SOUTH);
mainPanel.add(picLabel);
picLabel.setIcon(dice_images[0]);
buttonPanel.add(roll);
buttonPanel.add(save);
scorePanel.add(scoreField);
scoreField.setText(score);
roll.addActionListener(action);
save.addActionListener(output);
}
private void loadImage()
{
dice_images [0] = new ImageIcon("res/dice_img/die_01_sm.gif");
dice_images [1] = new ImageIcon("res/dice_img/die_02_sm.gif");
dice_images [2] = new ImageIcon("res/dice_img/die_03_sm.gif");
dice_images [3] = new ImageIcon("res/dice_img/die_04_sm.gif");
dice_images [4] = new ImageIcon("res/dice_img/die_05_sm.gif");
dice_images [5] = new ImageIcon("res/dice_img/die_06_sm.gif");
dice_images [6] = new ImageIcon("res/dice_img/die_01_sm.gif");
}
public static void main(String [] args){
DiceFrame frame = new DiceFrame();
frame.setDefaultLookAndFeelDecorated(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
class DiceActionListener implements ActionListener{
#Override
public void actionPerformed(ActionEvent e){}
}
class SaveActionListener implements ActionListener{
#Override
public void actionPerformed(ActionEvent e){}
}
I dont know what to put inside the actionPerformed method in order to not create another instance of the JFrame.

Do something like below code. Create a method that can change your image icon. Then call it from as part of your button click. Have a look at the comments.
import javax.swing.JFrame;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JButton;
import javax.swing.JTextArea;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class DiceFrame extends JFrame {
ImageIcon[] dice_images = new ImageIcon[7];
String score = "This is a test";
JPanel mainPanel, scorePanel, buttonPanel;
JLabel picLabel;
JTextArea scoreField;
JButton roll, save;
public DiceFrame(){
super();
mainPanel = new JPanel();
scorePanel = new JPanel();
buttonPanel = new JPanel();
roll = new JButton("Roll");
save = new JButton("Save");
picLabel = new JLabel();
scoreField = new JTextArea();
setSize(400,300);
setTitle("Dice Program");
loadImage();
getContentPane().add(mainPanel, BorderLayout.CENTER);
getContentPane().add(scorePanel, BorderLayout.EAST);
getContentPane().add(buttonPanel, BorderLayout.SOUTH);
mainPanel.add(picLabel);
picLabel.setIcon(dice_images[0]);
buttonPanel.add(roll);
buttonPanel.add(save);
scorePanel.add(scoreField);
scoreField.setText(score);
save.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) {
System.out.println("You clicked save");
}
});
roll.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) {
//call your icon change method with the index you want to change it to
changeIcon(3);
}
});
}
private void loadImage() {
//use a loop insted of repeting the add, but becareful if i < 10 because your file names need to match :)
for(int i = 0; i < 7; i++) {
dice_images [i] = new ImageIcon("res/dice_img/die_0" + i + "_sm.gif");
}
}
public static void main(String [] args) {
DiceFrame frame = new DiceFrame();
frame.setDefaultLookAndFeelDecorated(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
//create a method to change your icon
public void changeIcon(int imageIndex) {
picLabel.setIcon(this.dice_images[imageIndex]);
}
}

Why won't the JButtons, JLabels and JTextFields be displayed?

This code enables an employee to log in to the coffee shop system. I admit I have a lot of unneeded code. My problem is that when I run the program just the image is displayed above and no JButtons, JLabels or JTextFields.
Thanks in advance.
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.ImageIcon;
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import java.awt.image.BufferedImage;
import java.net.URL;
import javax.imageio.ImageIO;
public class login extends JFrame {
public void CreateFrame() {
JFrame frame = new JFrame("Welcome");
JPanel panel = new JPanel();
panel.setOpaque(true);
panel.setBackground(Color.WHITE);
panel.setLayout(new BorderLayout(1000,1000));
panel.setLayout(new FlowLayout());
getContentPane().add(panel);
ImagePanel imagePanel = new ImagePanel();
imagePanel.show();
panel.add(imagePanel, BorderLayout.CENTER);
frame.setContentPane(panel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
frame.add(panel);
}
public static void main(String... args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
new login().CreateFrame();
}
});
}
}
class GUI extends JFrame{
private JButton buttonLogin;
private JButton buttonNewUser;
private JLabel iUsername;
private JLabel iPassword;
private JTextField userField;
private JPasswordField passField;
public void createGUI(){
setLayout(new GridBagLayout());
JPanel loginPanel = new JPanel();
loginPanel.setOpaque(false);
loginPanel.setLayout(new GridLayout(3,3,3,3));
iUsername = new JLabel("Username ");
iUsername.setForeground(Color.BLACK);
userField = new JTextField(10);
iPassword = new JLabel("Password ");
iPassword.setForeground(Color.BLACK);
passField = new JPasswordField(10);
buttonLogin = new JButton("Login");
buttonNewUser = new JButton("New User");
loginPanel.add(iUsername);
loginPanel.add(iPassword);
loginPanel.add(userField);
loginPanel.add(passField);
loginPanel.add(buttonLogin);
loginPanel.add(buttonNewUser);
add(loginPanel);
pack();
Writer writer = null;
File check = new File("userPass.txt");
if(check.exists()){
//Checks if the file exists. will not add anything if the file does exist.
}else{
try{
File texting = new File("userPass.txt");
writer = new BufferedWriter(new FileWriter(texting));
writer.write("message");
}catch(IOException e){
e.printStackTrace();
}
}
buttonLogin.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
try {
File file = new File("userPass.txt");
Scanner scan = new Scanner(file);;
String line = null;
FileWriter filewrite = new FileWriter(file, true);
String usertxt = " ";
String passtxt = " ";
String puname = userField.getText();
String ppaswd = passField.getText();
while (scan.hasNext()) {
usertxt = scan.nextLine();
passtxt = scan.nextLine();
}
if(puname.equals(usertxt) && ppaswd.equals(passtxt)) {
MainMenu menu = new MainMenu();
dispose();
}
else if(puname.equals("") && ppaswd.equals("")){
JOptionPane.showMessageDialog(null,"Please insert Username and Password");
}
else {
JOptionPane.showMessageDialog(null,"Wrong Username / Password");
userField.setText("");
passField.setText("");
userField.requestFocus();
}
} catch (IOException d) {
d.printStackTrace();
}
}
});
buttonNewUser.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
NewUser user = new NewUser();
dispose();
}
});
}
}
class ImagePanel extends JPanel{
private BufferedImage image;
public ImagePanel(){
setOpaque(true);
setBorder(BorderFactory.createLineBorder(Color.BLACK,5));
try
{
image = ImageIO.read(new URL("https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQ8F5S_KK7uelpM5qdQXuaL1r09SS484R3-gLYArOp7Bom-LTYTT8Kjaiw"));
}
catch(Exception e)
{
e.printStackTrace();
}
GUI show = new GUI();
show.createGUI();
}
#Override
public Dimension getPreferredSize(){
return (new Dimension(430, 300));
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.drawImage(image,0,0,this);
}
}

Seems to me like you have a class login (which is a JFrame, but never used as one). This login class creates a new generic "Welcome" JFrame with the ImagePanel in it. The ImagePanel calls GUI.createGUI() (which creates another JFrame, but doesn't show it) and then does absolutely nothing with it, thus it is immediately lost.
There are way to many JFrames in your code. One should be enough, perhaps two. But you got three: login, gui, and a simple new JFrame().

How to read text file before GUI program runs

I've searched through the forums but keep coming up empty for a solution.
I'm making a sort of library with a GUI program. What I want is for it to save entries via a text file. I can create objects fine with the methods I have, and can save them to a file easily. The problem comes from starting up the program again and populating a Vector with values in the text file. The objects I'm adding have a String value, followed by 7 booleans. When I try to load up from file, the String value is empty ("") and all booleans are false.
How do I get it to read the text before starting the rest of the GUI and filling the Vector right?
EDIT: Sorry for being very vague about it all. I'll post the code, but it's about 337 lines long..
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Collections;
import java.util.Scanner;
import java.util.Vector;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
#SuppressWarnings("serial")
public class SteamLibraryGUI extends JFrame implements ActionListener
{
//For main window
private JButton exitButton, addEntry, editEntry, removeEntry;
private JLabel selectGame, gameCount;
private JComboBox<String> gameCombo;
private Vector<Game> gamesList = new Vector<Game>();
private Vector<String> titleList = new Vector<String>();
private int numGames = gamesList.size();
private int selectedGame;
//For add window
private JFrame addFrame;
private JLabel gameTitle = new JLabel("Title:");
private JTextField titleText = new JTextField(60);
private JCheckBox singleBox, coopBox, multiBox, cloudBox, controllerBox, achieveBox, pcBox;
private JButton addGame, addCancel;
//For edit window
private JFrame editFrame;
private JButton editGame, editCancel;
public SteamLibraryGUI()
{
setTitle("Steam Library Organizer");
addEntry = new JButton("Add a game");
editEntry = new JButton("Edit a game");
removeEntry = new JButton("Remove a game");
exitButton = new JButton("Exit");
selectGame = new JLabel("Select a game:");
gameCount = new JLabel("Number of games:"+numGames);
gameCombo = new JComboBox<String>(titleList);
JPanel selectPanel = new JPanel();
selectPanel.setLayout(new GridLayout(1,2));
selectPanel.add(selectGame);
selectPanel.add(gameCombo);
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new GridLayout(1,3));
buttonPanel.add(addEntry);
buttonPanel.add(editEntry);
buttonPanel.add(removeEntry);
JPanel exitPanel = new JPanel();
exitPanel.setLayout(new GridLayout(1,2));
exitPanel.add(gameCount);
exitPanel.add(exitButton);
Container pane = getContentPane();
pane.setLayout(new GridLayout(3,1));
pane.add(selectPanel);
pane.add(buttonPanel);
pane.add(exitPanel);
addEntry.addActionListener(this);
editEntry.addActionListener(this);
removeEntry.addActionListener(this);
exitButton.addActionListener(this);
gameCombo.addActionListener(this);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==addEntry)
addEntry();
if(e.getSource()==editEntry)
editEntry(gamesList.get(selectedGame));
if(e.getSource()==removeEntry)
{
removeEntry(selectedGame);
update();
}
if(e.getSource()==exitButton)
exitProg();
if(e.getSource()==gameCombo)
{
selectedGame = gameCombo.getSelectedIndex();
}
if(e.getSource()==singleBox)
singleBox.isSelected();
if(e.getSource()==coopBox)
coopBox.isSelected();
if(e.getSource()==multiBox)
multiBox.isSelected();
if(e.getSource()==cloudBox)
cloudBox.isSelected();
if(e.getSource()==controllerBox)
controllerBox.isSelected();
if(e.getSource()==achieveBox)
achieveBox.isSelected();
if(e.getSource()==pcBox)
pcBox.isSelected();
if(e.getSource()==addGame)
{
gamesList.add(new Game(titleText.getText(), singleBox.isSelected(), coopBox.isSelected(),
multiBox.isSelected(), cloudBox.isSelected(), controllerBox.isSelected(),
achieveBox.isSelected(), pcBox.isSelected()));
titleList.add(titleText.getText());
addFrame.dispose();
update();
}
if(e.getSource()==addCancel)
addFrame.dispose();
if(e.getSource()==editCancel)
editFrame.dispose();
if(e.getSource()==editGame)
{
gamesList.get(selectedGame).name = titleText.getText();
gamesList.get(selectedGame).single = singleBox.isSelected();
gamesList.get(selectedGame).coop = coopBox.isSelected();
gamesList.get(selectedGame).multi = multiBox.isSelected();
gamesList.get(selectedGame).cloud = cloudBox.isSelected();
gamesList.get(selectedGame).controller = controllerBox.isSelected();
gamesList.get(selectedGame).achieve = achieveBox.isSelected();
gamesList.get(selectedGame).pc = pcBox.isSelected();
titleList.remove(selectedGame);
titleList.add(titleText.getText());
editFrame.dispose();
update();
}
}
public void update()
{
Collections.sort(titleList);
Collections.sort(gamesList);
gameCombo.updateUI();
titleText.setText("");
gameCombo.setSelectedIndex(-1);
numGames = gamesList.size();
gameCount.setText("Number of games:"+numGames);
}
public void addEntry()
{
addFrame = new JFrame("Add Entry");
addFrame.setDefaultCloseOperation(EXIT_ON_CLOSE);
addFrame.getContentPane();
addFrame.setLayout(new GridLayout(3,1));
singleBox = new JCheckBox("Single-Player");
singleBox.setSelected(false);
coopBox = new JCheckBox("Coop");
coopBox.setSelected(false);
multiBox = new JCheckBox("MultiPlayer");
multiBox.setSelected(false);
cloudBox = new JCheckBox("Steam Cloud");
cloudBox.setSelected(false);
controllerBox = new JCheckBox("Controller Support");
controllerBox.setSelected(false);
achieveBox = new JCheckBox("Achievements");
achieveBox.setSelected(false);
pcBox = new JCheckBox("For New PC");
pcBox.setSelected(false);
addGame = new JButton("Add game");
addCancel = new JButton("Cancel");
JPanel titlePanel = new JPanel();
titlePanel.setLayout(new FlowLayout());
titlePanel.add(gameTitle);
titlePanel.add(titleText);
JPanel checkPanel = new JPanel();
checkPanel.setLayout(new FlowLayout());
checkPanel.add(singleBox);
checkPanel.add(coopBox);
checkPanel.add(multiBox);
checkPanel.add(cloudBox);
checkPanel.add(controllerBox);
checkPanel.add(achieveBox);
checkPanel.add(pcBox);
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new FlowLayout());
buttonPanel.add(addGame);
buttonPanel.add(addCancel);
addFrame.add(titlePanel);
addFrame.add(checkPanel);
addFrame.add(buttonPanel);
singleBox.addActionListener(this);
coopBox.addActionListener(this);
multiBox.addActionListener(this);
cloudBox.addActionListener(this);
controllerBox.addActionListener(this);
achieveBox.addActionListener(this);
pcBox.addActionListener(this);
addGame.addActionListener(this);
addCancel.addActionListener(this);
addFrame.pack();
addFrame.setVisible(true);
}
public void editEntry(Game g)
{
editFrame = new JFrame("Edit Entry");
editFrame.setDefaultCloseOperation(EXIT_ON_CLOSE);
editFrame.getContentPane();
editFrame.setLayout(new GridLayout(3,1));
singleBox = new JCheckBox("Single-Player");
singleBox.setSelected(g.single);
coopBox = new JCheckBox("Coop");
coopBox.setSelected(g.coop);
multiBox = new JCheckBox("MultiPlayer");
multiBox.setSelected(g.multi);
cloudBox = new JCheckBox("Steam Cloud");
cloudBox.setSelected(g.cloud);
controllerBox = new JCheckBox("Controller Support");
controllerBox.setSelected(g.controller);
achieveBox = new JCheckBox("Achievements");
achieveBox.setSelected(g.achieve);
pcBox = new JCheckBox("For New PC");
pcBox.setSelected(g.pc);
editGame = new JButton("Edit game");
editCancel = new JButton("Cancel");
titleText.setText(g.name);
JPanel titlePanel = new JPanel();
titlePanel.setLayout(new FlowLayout());
titlePanel.add(gameTitle);
titlePanel.add(titleText);
JPanel checkPanel = new JPanel();
checkPanel.setLayout(new FlowLayout());
checkPanel.add(singleBox);
checkPanel.add(coopBox);
checkPanel.add(multiBox);
checkPanel.add(cloudBox);
checkPanel.add(controllerBox);
checkPanel.add(achieveBox);
checkPanel.add(pcBox);
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new FlowLayout());
buttonPanel.add(editGame);
buttonPanel.add(editCancel);
editFrame.add(titlePanel);
editFrame.add(checkPanel);
editFrame.add(buttonPanel);
singleBox.addActionListener(this);
coopBox.addActionListener(this);
multiBox.addActionListener(this);
cloudBox.addActionListener(this);
controllerBox.addActionListener(this);
achieveBox.addActionListener(this);
pcBox.addActionListener(this);
editGame.addActionListener(this);
editCancel.addActionListener(this);
editFrame.pack();
editFrame.setVisible(true);
}
public void removeEntry(int g)
{
Object[] options = {"Yes, remove the game", "No, keep the game"};
int n = JOptionPane.showOptionDialog(null, "Are you sure you want to remove this game from the list?",
"Remove game?", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE, null, options, options[1]);
if (n==0)
{
gamesList.remove(g);
titleList.remove(g);
}
}
public void exitProg()
{
try
{
PrintWriter out = new PrintWriter("games.txt");
out.flush();
for(int i=0;i<gamesList.size();i++)
{
out.print(gamesList.get(i).toString());
}
out.close();
}
catch (FileNotFoundException e) {}
System.exit(0);
}
public static void main(String[] args)
{
SteamLibraryGUI frame = new SteamLibraryGUI();
frame.pack();
frame.setSize(600,200);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Scanner in = new Scanner("games.txt");
while(in.hasNextLine())
{
String line = in.nextLine();
String[] options = line.split("|");
Game g = new Game(options[0],Boolean.getBoolean(options[1]),
Boolean.getBoolean(options[2]),Boolean.getBoolean(options[3]),
Boolean.getBoolean(options[4]),Boolean.getBoolean(options[5]),
Boolean.getBoolean(options[6]),Boolean.getBoolean(options[7]));
frame.gamesList.add(g);
frame.titleList.add(options[0]);
System.out.println(g.toString());
}
in.close();
}
}
There's also a Game class, but it's simply 1 String, and then 7 booleans.

There were two significant bugs in the code. First, Scanner was constructed with a string parameter (which means that the Scanner scanned the string, not the file named by the string). Second, the pipe character "|" is a regular expression metacharacter. That is important because line.split() splits on regular expressions. Thus, the "|" has to be escaped. The main() function works fine if it is written as follows (with debugging output code included to show that each step is working correctly):
public static void main(String[] args)
{
SteamLibraryGUI frame = new SteamLibraryGUI();
frame.pack();
frame.setSize(600,200);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try
{
Scanner in = new Scanner(new File("games.txt"));
while(in.hasNextLine())
{
System.out.println("line = ");
String line = in.nextLine();
System.out.println(line);
String[] options = line.split("\\|");
System.out.println("Options = ");
for (String s : options)
{
System.out.println(s);
}
Game g = new Game(options[0],Boolean.getBoolean(options[1]),
Boolean.getBoolean(options[2]),Boolean.getBoolean(options[3]),
Boolean.getBoolean(options[4]),Boolean.getBoolean(options[5]),
Boolean.getBoolean(options[6]),Boolean.getBoolean(options[7]));
frame.gamesList.add(g);
frame.titleList.add(options[0]);
System.out.println(g.toString());
}
in.close();
} catch (IOException x)
{
System.err.println(x);
}
}
There is one other important Gotcha: The method exitProg() writes the "games.txt" file out again before the program finishes. This creates a problem if the file was read incorrectly in the first place because the wrong data will be written back to the file. During testing, this means that even when the reading code has been corrected, it will still read the erroneous data that was written from a previous test run.
My preference in this situation is would be to isolate all the reading and writing code for "game.txt" inside the Game class (which makes it easier to verify that the reading and writing formats are identical) and only write the code to write the data back out once I'd written and tested the reading code, which would avoid this Gotcha.